How long it takes and what are the activities in Space center? Is half day is Ok or a full day is required to cover space center visit? We are arriving during day time so our half day will be in flight and we would like to use our half of that day

Half a day is fine. Make sure you do the 2 and half hour guided tour. It's included with admission

It depends on what your interest are. I would go in line and plan your activities it is a full day but if in a time crunch highlight what you think you must see. There is nothing I would want to skip when I go again

I think you can crammed it in a day. Maybe day and a half to see everything. If you are only giving it half a day then make sure to take the bus tour and once you get to destination, after the first presentation make sure you take the guided tour right after that. It's short but you will learn a lot.

You really should give it a full day. A lot to see. Taking the bus tour is a must.

Noted with Thanks